- ASPARAGINE DERIVATIVES AND METHODS OF USE THEREOF
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The present invention relates to compounds of formulas (A) and (I), pharmaceutically acceptable salts thereof, and solvates of any of them, pharmaceutical compositions comprising them, methods of preparation thereof, intermediate compounds useful for the preparation thereof, and methods of treatment or prophylaxis of diseases, in particular cancer, such as colorectal cancer, using these. (A) (I)
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Paragraph 001027; 001029-001030
(2021/12/31)
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- A continuous homologation of esters: An efficient telescoped reduction-olefination sequence
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A continuous protocol for the two-carbon homologation of esters to α,β-unsaturated esters is described. This multireactor homologation telescopes an ester reduction, phosphonate deprotonation, and Horner-Wadsworth-Emmons olefination, thus converting a three-operation procedure into a single, uninterrupted system that eliminates the need for isolation or purification of the aldehyde intermediates. The homologated products are obtained in high yield and selectivity.
- Webb, Damien,Jamison, Timothy F.
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supporting information; experimental part
p. 2465 - 2467
(2012/07/01)
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- Enantioselective synthesis of allylboronates bearing a tertiary or quaternary B-substituted stereogenic carbon by NHC-Cu-catalyzed substitution reactions
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Allylic substitutions that afford α-substituted allylboronates bearing B-substituted tertiary or quaternary carbon stereogenic centers are presented. C-B bond-forming reactions, catalyzed by chiral bidentate Cu-NHC complexes, are performed in the presence of commercially available bis(pinacolato)diboron. Transformations proceed in high yield (up to >98%) and site selectivity (>98% SN2′), and in up to >99:1 enantiomer ratio. Trans- or cis-disubstituted alkenes can be used; alkyl- (linear as well as branched) and aryl-trisubstituted allylic carbonates serve as effective substrates. Allylboronates that bear a quaternary carbon center are air-stable and can be easily purified by silica gel chromatography; in contrast, secondary allylboronates cannot be purified in the same manner and are significantly less stable. Oxidation of the enantiomerically enriched products furnishes secondary or tertiary allylic alcohols, valuable small molecules that cannot be easily obtained in high enantiomeric purity by alternative synthesis or kinetic resolution approaches.
- Guzman-Martinez, Aikomari,Hoveyda, Amir H.
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supporting information; scheme or table
p. 10634 - 10637
(2010/11/05)
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- Reaction of silyl ketene acetals with epoxides: A new method for the synthesis of γ-butanolides
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Titanium tetrachloride promoted reaction of silyl ketene acetals with epoxides, followed by acidic work-up, affords butanolides in moderate/good yields. With epihalohydrins the reaction is regioselective and occurs at the less substituted end of the epoxide; the γ-haloalkyl-γ-butanolides thus obtained can be further transformed into various products. Graphical Abstract
- Maslak, Veselin,Matovi?, Radomir,Sai?i?, Radomir N.
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p. 8957 - 8966
(2007/10/03)
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- Practical synthesis of Abbott amino-diol: A core unit of the potent renin inhibitor Zankiren
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Abbott amino-diol (2S,3R,4S)-2-amino-1-cyclohexyl-6-methyl heptane-3,4- diol 1, a main structural constituent of the orally active renin inhibitor Zankiren has been synthesized using Sharpless asymmetric aminohydroxylation as the key step.
- Chandrasekhar,Mohapatra, Suchismita,Yadav
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p. 4763 - 4768
(2007/10/03)
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- A short and efficient enantioselective synthesis of cyclohexylnorstatine, a key component of a renin inhibitor
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A catalytic asymmetric synthesis of ethyl (2R,35)-N-(p- toluenesulfonyl)-3-amino-4-cyclohexyl-2-hydroxybutyrate 7 in 96% ee from cheaply available cyclohexanone is described employing Sharpless asymmetric aminohydroxylation as the key step.
- Upadhya,Sudalai
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p. 3685 - 3689
(2007/10/03)
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- A convenient, stereodivergent approach to the enantioselective synthesis of N-Boc-aminoalkyl epoxides
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An efficient, stereodivergent and enantioselective synthesis of N-Boc-aminoalkyl epoxides has been developed. Starting from enantiomerically enriched anti N-diphenylmethyl-3-amino-1,2-diols, and after a change in the nitrogen protecting group, an intramol
- Castejon, Patricia
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p. 3019 - 3022
(2007/10/02)
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- AN IMPROVED PROCEDURE FOR THE TWO CARBON HOMOLOGATION OF ESTERS TO α,β-UNSATURATED ESTERS
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Treatment of esters with diisobutylaluminium hydride (DIBAL) in the presence of lithio-trialkylphosphonoacetate results in improved yields of the homologated α,β-unsaturated esters.The problematic overreduction, which has previously observed in the half reduction of esters using DIBAL, is minimal (3percent) under these conditions.
- Takacs, James M.,Helle, Mark A.,Seely, Franklin L.
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p. 1257 - 1260
(2007/10/02)
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